The Zepbound and Mounjaro KwikPen: 4 doses in one pen
One KwikPen holds 4 weekly doses at a single fixed strength, and both FDA labels, read August 31, 2026, say to throw the pen away after the fourth dose even with medicine left in it. The dial does not choose the milligrams. It turns to one stop, and the strength is set by the prescription.
Six KwikPens, one strength each
Lilly sells Zepbound and Mounjaro in four presentations: a single-dose pen, a single-dose vial, a multi-dose vial and the KwikPen. The KwikPen and the multi-dose vial each hold 4 doses. The other two hold one. Both labels print the same table.
The single-patient-use KwikPen presentations, identical on the Zepbound and Mounjaro labels. Read from the current FDA prescribing information on DailyMed, checked August 31, 2026.
| Dose per injection | Total in the pen | Concentration |
|---|---|---|
| 2.5 mg | 10 mg/2.4 mL | 4.17 mg/mL |
| 5 mg | 20 mg/2.4 mL | 8.33 mg/mL |
| 7.5 mg | 30 mg/2.4 mL | 12.5 mg/mL |
| 10 mg | 40 mg/2.4 mL | 16.7 mg/mL |
| 12.5 mg | 50 mg/2.4 mL | 20.8 mg/mL |
| 15 mg | 60 mg/2.4 mL | 25 mg/mL |
Read the first column as the prescription and the second as the arithmetic behind it. A 5 mg KwikPen holds 20 mg because 5 mg times four weeks is 20 mg.
What the dose does to your bill
LillyDirect prices Zepbound by dose. Every step it publishes, checked August 31, 2026.
| Dose | Cost / mo |
|---|---|
| Zepbound vial, starter dose (2.5mg) | $299/mo |
| Zepbound vial, maintenance (5mg) | $399/mo |
| Zepbound vial, higher doses (7.5mg+) | $449/mo |
| Program | At the dose you stay on | At the top dose it publishes |
|---|---|---|
| CVS MinuteClinic | $428/mo | $528/mo |
| Walgreens Weight Management | $448/mo | $548/mo |
| LifeMD | $498/mo | $698/mo |
| Ro Body | $548/mo | $598/mo |
| Hims & Hers | $598/mo | Not published |
Each figure is the total a month, membership and fees in, read off the program's own published pricing. A program that publishes no Zepbound price is not listed. See every price we track.
Compare every Zepbound route at its maintenance price →
The pen you are given changes what the drug costs
Same milligrams, different packaging. A US pharmacy pays more for the single-dose pens at every dose Lilly publishes, and the gap is widest at the starting doses.
| Dose | KwikPen | Single-dose pens | Times as much |
|---|---|---|---|
| 2.5 mg | $482/mo | $1,052/mo | 2.18x |
| 5 mg | $482/mo | $1,052/mo | 2.18x |
| 7.5 mg | $482/mo | $1,052/mo | 2.18x |
| 10 mg | $675/mo | $1,052/mo | 1.56x |
| 12.5 mg | $678/mo | $1,052/mo | 1.55x |
| 15 mg | $672/mo | $1,051/mo | 1.56x |
Acquisition cost is not your price and not pharmacy margin. It is the national average a pharmacy paid, published weekly by CMS in the public domain.
What the dial actually does
The KwikPen has a dose knob and a dose window, which reads like a device you set. It is not. The label calls it "a disposable multi-dose single-patient-use prefilled pen" that "contains 4 fixed doses, one dose taken weekly," and tells you to "turn the dose knob all the way until it stops AND the icon is in dose window."
The knob has a second position. Turned until you hear two clicks, it sits at the prime position, which is not a dose.
After the fourth injection the label says the pen prevents you from dialing a full dose, and the instruction is to throw it away with the medicine still in it. Each pen is filled with extra volume so it can be primed four times, which is why there is liquid left at the end. The label also says not to transfer the medicine into a syringe and not to share a pen, even with a new needle.
Priming, in the label's own steps
Prime before each weekly injection. The label gives one procedure and both drugs carry it identically.
- Attach a new pen needle, then turn the dose knob slowly until you hear 2 clicks and the extended line shows in the dose window. That is the prime position.
- Hold the pen with the needle pointing up and tap the cartridge holder to collect air at the top.
- Push the dose knob in until it stops, then hold it and count slowly to 5. The icon must show in the dose window. Do not inject this into your body.
A drop of medicine at the needle tip means the pen primed. If nothing comes out, the label says to repeat those steps no more than 2 further times, then change the pen needle and repeat once more, then call Lilly at 1-800-545-5979.
Three clocks run on an in-use KwikPen
An unopened KwikPen keeps to its expiration date in the fridge. Once it is in use, the label runs three deadlines at once and the earliest one wins.
| Product | In the fridge | Out of the fridge |
|---|---|---|
| Zepbound multi-dose vial or KwikPen, unopened | 36 to 46 F until the expiration date | If stored at room temperature, up to 86 F, throw it away after 30 days. |
| Zepbound multi-dose vial or KwikPen, in use | 36 to 46 F | Up to 86 F in the original carton. Throw it away after a total of 30 days at room temperature, 30 days from first use, or four weekly doses, whichever comes first, even with medicine left in it. |
| Mounjaro multi-dose vial or KwikPen, unopened | 36 to 46 F until the expiration date | If stored at room temperature, up to 86 F, throw it away after 30 days. |
| Mounjaro multi-dose vial or KwikPen, in use | 36 to 46 F | Up to 86 F in the original carton. Throw it away after a total of 30 days at room temperature, 30 days from first use, or four weekly doses, whichever comes first, even with medicine left in it. |
Do not freeze a KwikPen and do not use one that has been frozen.
The missed-dose window
Within 4 days (96 hours), take it. Past 4 days, skip it and take the next dose on the regular day. The Mounjaro label prints the same rule. Changing the injection day is allowed as long as at least 3 days, 72 hours, separate the two doses. Neither label says anything about restarting after a longer gap, and that silence is worth taking to a prescriber rather than filling in.
Frequently asked questions
How many doses are in one KwikPen?
Four. The dosage-forms table on both labels prints "4 doses per KwikPen" for every strength, one dose a week, so a pen is a month. After the fourth dose the pen locks and will not dial a full dose again.
Do I dial my dose on the KwikPen?
No. The label calls it a pen with 4 fixed doses and says to "turn the dose knob all the way until it stops" for each weekly injection. The milligrams come from which pen you were prescribed, not from where you stop the knob.
Do I have to prime a KwikPen every week?
Yes, before each weekly injection. Turn the knob until you hear 2 clicks, hold the pen needle up and tap the cartridge holder, then push the knob in and hold it while you count to 5. A drop at the needle tip means it primed.
There is medicine left in my pen. Can I use it?
The label says no. The pen carries extra volume so it can be primed, and the instruction is to throw the pen away after 4 doses including the unused medicine. It also says not to transfer the medicine into a syringe.
What if I miss a KwikPen dose?
Within 4 days (96 hours), take it. Past 4 days, skip it and take the next dose on the regular day. The Mounjaro label carries the same window.
Does a higher KwikPen strength cost more?
On some programs yes and on others no. The cheapest Zepbound route we track is CVS MinuteClinic at $428 a month at the dose you stay on. The biggest climb is LifeMD, where the top dose costs $200 a month more.
Every dosage sentence on this page is written to a prescriber, not to you. The pen you are given, the strength on it and what to do about a missed week are all decisions for the person writing the prescription. Take the label language to the appointment.
Sources
Evidence checked August 31, 2026
Every figure above is taken from the document beside it, the FDA label or the trial that produced it, so you can read the source instead of trusting us. No clinician reviews these pages. What that means.
- The KwikPen strengths, the four-dose rule, the priming steps, the discard instruction, the 96-hour missed-dose window and the storage clocks for ZepboundFDA prescribing information for Zepbound (DailyMed, revised August 2026)
- The same device sentences on the Mounjaro labelFDA prescribing information for Mounjaro (DailyMed, revised August 2026)
- What a US pharmacy pays to acquire a month of Zepbound in a KwikPen against the same dose in single-dose pensCMS National Average Drug Acquisition Cost file effective August 19, 2026
